In one aspect, this invention relates to a process for isomerizing monoolefins containing a terminal double bond to monoolefins containing an internal double bond. In another aspect, this invention relates tot he isomerization of a butene-1 containing feed, in the presence of a noble metal catalyst, so as to produce butene-2. In a further aspect, this invention relates to pretreating monoolefin-containing isomerization feeds so as to remove catalyst poisons therefrom.
It is known to isomerize monoolefins containing a terminal double bond, in particular butene-1, to monoolefins containing an internal double bond, in the presence of a Group VIII noble metal catalyst, in particular Pd/Al.sub.2 O.sub.3. It is also known to pretreat monoolefin containing isomerization feeds so as to remove therefrom impurities which can adversely affect the isomerization activity of the noble metal catalyst. The instant invention provides an improved process for pretreating monoolefin isomerization feeds.